Bars in Gantt chart showing values of certain cells?

I had created a gantt chart from my excel datasheet and I am required to programme the vb code such that when I move my mouse cursor over a bar in the gantt chart....it will show the values in 2 certain cells. Or is there a better way to show the values? Can anyone show me any example/code examples??

Can you provide us a sample workbook where you see this gant chart and exactly which pieces in the chart you want highlighted/displayed?